Change of Evaporation in Recent 50 Years in Hebei Region

Based on the available observation data of 1956～2000 from 68 meteorological stations in the Hebei region ,the evaporation changesin this area have been analyzed. The results show: In recent 50 years, the evaporation is declined remarkably in the Hebei region, and in different area of this region.The characteristics of the evaporation's variation in every senson are similar. The extentof change is maximumin spring, and minimun in winter. In 60's ,The evarage evaporation is maximum in the most of the Hebei region, and in different area. The evaporation is decreased from 60's to 90's.The reason of evaporation decline is directly correlatiedto the minish of evarage wind speed.